Single photon sources are characterized by the fact that they emit only individual photons in a controllable way, whereby the simultaneous emission of several photons is suppressed. It is technologically very challenging to reproducibly realize electrically controllable single photon sources that exhibit such a pronounced photon anti-bunching, in which several individually emitted photons can be clearly separated from each other. For capacitive reasons and with regard to the emission rate, the single photon sources can only usually be used in the low frequency range between a few kHz and a few MHz. In addition, room temperature operation is not possible of most conventional single photon sources due to insufficient photon anti-bunching. These are some of the main problems that have limited the commercial use of single photon sources so far.
It could therefore be helpful to provide an efficient and widely applicable single photon source and a reliable method for the controlled generation of photons, in particular of individual photons.